T-square.



E. B. WILES. I

V T-SQUARE. APPLICATION FILED MAR. 26, 1908.

Patented Nov. 10, 1908.

1 III I! I I UNITED STA'I YE IETENT OFFICE.

EDWIN B. WILES, OF NEW YORK, N. Y., ASSIGNOR OF FORTY-FIVE ONE-HUNDREDTHS TO HIMSELF AND FIFTY-FIVE ONE-HUNDREDTHS TO ERNEST A. VAN VLEOK, OF NEW YORK, N. Y.

T-S QUARE Patented Nov. 10, 1908.

Application filed March 26, 1908. Serial No. 423,300.

To all whom it may concern:

Be it known that I, EDWIN B. lVILns, a citizen of the United States, residing in the borough of Bronx, city, county, and State of New York, have invented an Improvement in T-Squares, of which the following is a specification.

This invention relates to an improvement in T squares. Heretofore so far as I am aware, T squares have commonly been made with the blade fixed in the head, which latter is either a unitary structure or a divided member, and when the head is divided, one part thereof has generally been fixed to the blade and the other part made adjustable by a clamp screw or other suitable means. In T squares of this construction, the parts thereof are not readily separable and from the very nature of an instrument of this description, it occupies a useless amount ofspace when not in use or in being carried about.

The object of my invention is therefore the provision of a T square or similar instrument Whose parts are readily separable when not in use, and the further object of my invention is to provide a T square in which the edges of the blade may be readily trued without impairing the instrument.

In carrying out my invention, the T square preferably comprises a head, a blade and means on one of these members adapted to enter a portion provided therefor in the other member to separably join and frictionally hold the parts together.

In the drawing, Figure 1 is a plan view of a T square in which my present invention is embodied. Fig. 2 is a plan view of a portion of the head member with the blade removed. Fig. 3 is a partial end view of the same and Fig. 4: is an inverted plan view of the end of the blade member. Fig. is an edge view of the same. Fig. 6 is an enlarged cross section taken on the line :11, m, Fig. 1'.

Referring particularly to the drawings, a designates the head member of a T square and Z) the blade member thereof, which parts as will be understood, may be made of metal, hard rubber or any other suitable material. The head member a in one side thereof is provided with a recess 0, the opposite edges of which are preferably converging and undercut as indicated at (Z. One end of the blade member 5 is provided with a raised portion indicated at e which as will be understood, may be made of any suitable material and may be glued or connected to the blade member by screws, or secured thereto in any other desired manner. The opposite edges of this raised portion 6, adjacent to the converging edges of the blade member 6, are also converging and undercut as indicated at f, the angle of convergence of the edges of the member 6 being the same as that of the edges of the recess 0 and preferably the angle at which the edges of the raised member 6 are undercut, corresponds with the angle at which the edges of the recess 0 are undercut, so that the raised member e is adapted to enter and fit within the recess a to separably join the parts together in frictional contact, and also the thickness of the raised member 6 is preferably slightly less than the depth of the recess 0 so that the fit will be free and there will also be a binding frictional contact between those portions 9 of the underside of the blade 6 and the adjacent portions of the said member a.

I claim as my invention:

1. A T-square comprising a blade and a head, a raised engaging portion upon one of said parts in a plane beyond one surface thereof and the other part having a recess below one surface thereof to receive said raised engaging portion of the other member when said surfaces come in juxtaposition to connect said members and hold them together frictionally in a separable relation.

2. A T square comprising a head having a recess, a blade, a raised portion having undercut converging edges secured to the said blade and adapted to enter the recess in the said head to separably join and frictionally hold the members together.

3. A T square comprising a head having a recess extending across the same and whose edges are converging and undercut, a blade and a raised portion secured to the surface of the said blade at one end thereof, the opposite edges of the said raised portion being converging and undercut and adapted to enter the said recess in the said head.

Signed by me this 21st day of March, 1908.

EDNIN B. ILES.

Witnesses:

GEO. T. PINGKNEY, BERTI-IA M. ALLEN. 

